Slashdot Mirror
Mystery of the Coldest Spot In the CMB Solved
StartsWithABang writes: The cosmic microwave background is a thing of beauty, as not only does its uniform, cold temperature reveal a hot, dense past that began with the hot Big Bang, but its fluctuations reveal a pattern of overdensities and underdensities in the very early stages of the Universe. It's fluctuations just like these that give rise to the stars, galaxies, groups and clusters that exist today, as well as the voids in the vast cosmic web. But effects at the surface of last scattering are not the only ones that affect the CMB's temperature; if we want to make sure we've got an accurate map of what the Universe was born with, we have to take everything into account, including the effects of matter as it gravitationally grows and shrinks. As we do exactly this, we find ourselves discovering the causes behind the biggest anomalies in the sky, and it turns out that the standard cosmological model can explain it all.
Isn't the whole point of this area is that is anomalous? at least in comparison to all the other areas of the CMB? yes there are other 'cooler' areas but this seems to be the only one of this magnitude. If this was a common feature across the whole CMB then the cold spot could be considered as part of the standard cosmological model surely?
Aw, boring. I was hoping that everyone was wrong and we get some new physics. Misconception of scientists number one, scientists (and me) like to be shown wrong so we can go and investigate and discover new knowledge. The day it turns out that we know everything will be a very sad day indeed.
http://www.mueller-public.de - My site http://www.anr-institute.com/ - Advanced Natural Research Institute
Something can be uniform and fluctuating at the same time. All that's required is that the fluctuations follow the same, regular pattern everywhere. I have no idea whether this is true for the CMB, however.
It is true. Further, the fluctuations are tiny - at the parts per million level. It took 28 years after the CMB was discovered to detect any fluctations at all, requiring a sophisticated space probe (COBE) to do it.
Asserting that the CMB is "not uniform" because of these fluctuations is rather like saying the Bonneville Salt Flats are not really flat at all since the surface has millimeter scale irregularities, or your polished marble dining room floor isn't flat since it has micron sized irregularities.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj
Inflation was cooked up to explain most of that after the fact, though, so it's unsurprising that it does. The fundamental problem with inflation is that too much is tunable. Penrose's cyclic cosmology explains all the same stuff, and at least has the decency to make some bizarre (and very likely false) predictions outside of the early universe.
Theories of the very early universe that require new fields that there's a way to detect today are interesting. Certainly there are ideas to explain dark energy as an extension of inflation that fit that bill. But theories that propose a bunch of cool new physics that all conveniently vanished early on are a bit sketchy, at least until we can somehow make an equivalent of WMAP for the neutrino background radiation, and observe the very early universe directly. I hope I live to see that!
Socialism: a lie told by totalitarians and believed by fools.
I still choose to believe that the CMB cold spot is a parallel universe entangled with ours, and I want my belief treated with respect. #teachthecontroversy